first day code compiles under Win/Mac and Linux, took out polling which required POSIX, used std::thread instead, less complicated than I thought

README.md

@@ -1,5 +1,12 @@
 # zmqprototype
-Prototype code for cross platform zmq rep-req render node
+[ALPHA CODE] My learning project to prototype a cross platform zmq rep-req render node
+
+- This is the code before integration with bella_engine_sdk
+
+server starts in pubkey server mode, allowing one client to grab the pubkey
+-   keypairs are generated on every start
+- requires port 5555, 5556, 5557
+client 
 
 ###Build 
 
@@ -33,6 +40,11 @@ g++ server.cpp -o server -lzmq -Wl,-rpath,.
 ```
 g++ -std=c++11 server.cpp -o server -I../libzmq/include -I../cppzmq -L../libzmq/build/lib -lzmq -Wl,-rpath,. 
 g++ -std=c++11 server.cpp -o server -I../libzmq/include -I../cppzmq -L../libzmq/build/lib -lzmq -Wl,-rpath,. 
+
+cl /std:c++17 client.cpp -Fe:client.exe -Ic:\Users\cupcake\github\vcpkg\installed\x64-windows\include\ /link c:\Users\cupcake\github\vcpkg\installed\x64-windows\lib\libzmq-mt-4_3_5.lib
+
+cl /std:c++17 server.cpp -Fe:server.exe -Ic:\Users\cupcake\github\vcpkg\installed\x64-windows\include\ /link c:\Users\cupcake\github\vcpkg\installed\x64-windows\lib\libzmq-mt-4_3_5.lib
+
 ```
 
 

client.cpp

@@ -8,11 +8,127 @@
 #include <string>
 #include <vector>
 #include <chrono>
-#include <unistd.h> // For STDIN_FILENO
-
-// dynamic char
 #include <vector>       
 
+#include <atomic>
+#include <condition_variable>
+#include <mutex>
+
+// Atomic variable to store the counter value
+std::atomic<int> counter(0);
+std::atomic<bool> heartbeat_state (true);
+// Condition variable to signal the counter thread
+std::condition_variable cv;
+// Mutex to protect shared data
+std::mutex mtx;
+// Flag to indicate if the counter should reset
+std::atomic<bool> shouldReset(false);
+
+void command_thread(std::string server_pkey, std::string client_pkey, std::string client_skey) {
+    const size_t chunk_size = 32768;
+    zmq::context_t ctx;
+    zmq::socket_t command_sock (ctx, zmq::socket_type::req);
+    command_sock.set(zmq::sockopt::sndtimeo, 10000);
+    command_sock.set(zmq::sockopt::rcvtimeo, 10000);
+    command_sock.set(zmq::sockopt::curve_serverkey, server_pkey);
+    command_sock.set(zmq::sockopt::curve_publickey, client_pkey);
+    command_sock.set(zmq::sockopt::curve_secretkey, client_skey);
+    command_sock.set(zmq::sockopt::linger, 1); // Close immediately on disconnect
+    command_sock.connect("tcp://localhost:5556");
+
+    while (true) {
+        std::string input;
+        std::getline(std::cin, input); 
+        zmq::message_t msg_command (input);
+        command_sock.send(msg_command, zmq::send_flags::none);
+        std::cout << "Sent: " << input.data() << std::endl;
+
+        zmq::message_t zmq_response;
+        command_sock.recv(zmq_response, zmq::recv_flags::none);
+        std::string response(static_cast<char*>(zmq_response.data()), zmq_response.size()-1);
+        std::cout << "Server Response: " << response << response.size() << std::endl;
+
+        if(response=="ACK") { // Check server is ok to move on
+            std::cout << "kACKServer Response: " << response << std::endl;
+
+            if(input == "exit") {
+                break;
+            } else if(input == "send") {
+                std::string read_file = "./orange-juice.bsz";
+                std::cout << "sending\n";
+                std::ifstream binaryInputFile;
+                binaryInputFile.open(read_file, std::ios::binary);// for reading
+                if (!binaryInputFile.is_open()) {
+                    std::cerr << "Error opening file for read" << std::endl;
+                    zmq::message_t zmsg1("ERR");
+                    command_sock.send(zmsg1, zmq::send_flags::none); 
+                    zmq::message_t z_in;
+                    command_sock.recv(z_in); // Wait for acknowledgment from server
+                    std::cout << z_in << std::endl;
+                } else {
+           
+                    std::vector<char> send_buffer(chunk_size);
+                    std::streamsize bytes_read_in_chunk;
+                    while (true) {
+                        binaryInputFile.read(send_buffer.data(), chunk_size); // read the file into the buffer
+                        bytes_read_in_chunk = binaryInputFile.gcount(); // Actual bytes read
+                        if(bytes_read_in_chunk > 0){
+                            //std::cout << bytes_read_in_chunk << std::endl;
+                            zmq::message_t message(send_buffer.data(), bytes_read_in_chunk);
+                            zmq::message_t z_in;
+                            command_sock.send(message, zmq::send_flags::none);
+                            command_sock.recv(z_in); // Wait for acknowledgment from server
+                        } else {
+                            break;
+                        }
+                    }
+                    // Send an empty message to signal end of file
+                    command_sock.send(zmq::message_t(), zmq::send_flags::none);
+                    zmq::message_t z_in;
+                    command_sock.recv(z_in); // Wait for acknowledgment from server
+                }
+            }
+        }
+    }
+    command_sock.close();
+    ctx.close();
+}
+
+void heartbeat_thread(std::string server_pkey, std::string client_pkey, std::string client_skey) {
+    zmq::context_t ctx;
+    zmq::socket_t heartbeat_sock (ctx, zmq::socket_type::req);
+    heartbeat_sock.set(zmq::sockopt::curve_serverkey, server_pkey);
+    heartbeat_sock.set(zmq::sockopt::curve_publickey, client_pkey);
+    heartbeat_sock.set(zmq::sockopt::curve_secretkey, client_skey);
+    heartbeat_sock.connect("tcp://localhost:5555");
+    int heartbeat_count = 0;
+    std::vector<zmq::pollitem_t> items = {};
+    while (true) {
+        // Increment the counter every 10 milliseconds
+        std::this_thread::sleep_for(std::chrono::milliseconds(1000));
+        //std::cout << "beat" << std::endl;
+        std::string msg_string = "BEAT" + std::to_string(heartbeat_count++);
+        zmq::message_t msg_heartbeat (msg_string);
+        heartbeat_sock.send(msg_heartbeat, zmq::send_flags::none);
+
+
+        // Wait for response (poll for ZMQ_POLLIN)
+        zmq::pollitem_t response_item = { heartbeat_sock, 0, ZMQ_POLLIN, 0 };
+        zmq::poll(&response_item, 1, 100); // Wait for response with timeout
+        if (response_item.revents & ZMQ_POLLIN) {
+            zmq::message_t msg_response;
+            heartbeat_sock.recv(msg_response, zmq::recv_flags::none);
+            //std::cout << "Heartbeat Response: " << std::endl;
+        } else {
+            std::cout << "Bella Server is unavailable" << std::endl;
+            heartbeat_state = false;
+        }
+    }
+    heartbeat_sock.close();
+    ctx.close();
+}
+
+
 std::string get_pubkey_from_srv() {
     // No authentication is used, server will give out pubkey to anybody
     // Could use a unique message but since socket is unencrypted this provides
@@ -33,30 +149,27 @@ std::string get_pubkey_from_srv() {
 
     try {
         zmq::send_result_t send_result = pubkey_sock.send(z_out, zmq::send_flags::none);
-        std::cout << "TRY" << std::endl;
     } catch (const zmq::error_t& e) {
         std::cout << "ERROR" << std::endl;
     }
 
-    std::cout << "RECEVIE" << std::endl;
+    std::cout << "bellazmq connecting to server..." << std::endl;
-
     zmq::message_t z_in;
     pubkey_sock.recv(z_in);
     std::string pub_key = z_in.to_string();
     pubkey_sock.close();
     ctx.close();
+    std::cout << "connection successful" << std::endl;
     return pub_key;
 }
 
 int main()
 {
-    try 
-    {
     const size_t chunk_size = 32768;
     // Dynamically create keypair, every run is bespoke
     // [TODO] send pubkey to server, mkdir, render to that dir
-        char client_skey[128] = { 0 };
+    char client_skey[41] = { 0 };
-        char client_pkey[128] = { 0 };
+    char client_pkey[41] = { 0 };
     if ( zmq_curve_keypair(&client_pkey[0], &client_skey[0])) {
         // 1 is fail
         std::cout << "\ncurve keypair gen failed.";
@@ -65,141 +178,27 @@ int main()
 
     // Get server pubkey, set client keypair
     std::string server_pkey = get_pubkey_from_srv();
-        if(server_pkey.empty()) {
+    /*if(server_pkey.empty()) {
         std::cout << "Server is Down" << std::endl;
-            return 1;
+        heartbeat_state = false;
-        }
-        
-        zmq::context_t ctx(1);
-
-        // Create zmq sockets
-        zmq::socket_t heartbeat_sock (ctx, zmq::socket_type::req);
-        zmq::socket_t command_sock (ctx, zmq::socket_type::req);
-
-        // Encrypt heartbeat socket 
-        heartbeat_sock.set(zmq::sockopt::curve_serverkey, server_pkey);
-        heartbeat_sock.set(zmq::sockopt::curve_publickey, client_pkey);
-        heartbeat_sock.set(zmq::sockopt::curve_secretkey, client_skey);
-
-        // Encrypt command socket 
-        command_sock.set(zmq::sockopt::curve_serverkey, server_pkey);
-        command_sock.set(zmq::sockopt::curve_publickey, client_pkey);
-        command_sock.set(zmq::sockopt::curve_secretkey, client_skey);
-        
-        std::cout << "keypair" << std::endl; 
-
-        // Set receive timeout to 1000 milliseconds
-        //command_sock.set(zmq::sockopt::sndtimeo, 100000);
-        //command_sock.set(zmq::sockopt::rcvtimeo, 1000);
-        command_sock.set(zmq::sockopt::linger, 1); // Close immediately on disconnect
-
-        //zmq::context_t ctx(1);
-        //zmq::socket_t heartbeat_sock (ctx, zmq::socket_type::req);
-        //zmq::socket_t command_sock (ctx, zmq::socket_type::req);
-        //sock.set(zmq::sockopt::sndtimeo, 10000);
-        //sock.set(zmq::sockopt::rcvtimeo, 10000);
-        //command_sock.set(zmq::sockopt::linger, 1); // Close immediately on disconnect
-                                           //
-        heartbeat_sock.connect("tcp://localhost:5555");
-        command_sock.connect("tcp://localhost:5556");
-
-        std::vector<zmq::pollitem_t> items = {
-            { heartbeat_sock, 0, ZMQ_POLLOUT, 0 },   // Monitor sender1 for send readiness
-            { 0, STDIN_FILENO, ZMQ_POLLIN, 0 }      // Monitor std::cin
-        };
-
-        int heartbeat_count = 0;
-        while (true) {
-            zmq::poll(items, 100); 
-            if (items[0].revents & ZMQ_POLLOUT) {
-                std::string msg_string = "BEAT" + std::to_string(heartbeat_count++);
-                zmq::message_t msg_heartbeat (msg_string);
-                heartbeat_sock.send(msg_heartbeat, zmq::send_flags::none);
-
-                // Wait for response (poll for ZMQ_POLLIN)
-                zmq::pollitem_t response_item = { heartbeat_sock, 0, ZMQ_POLLIN, 0 };
-                zmq::poll(&response_item, 1, 100); // Wait for response with timeout
-
-                if (response_item.revents & ZMQ_POLLIN) {
-                    zmq::message_t msg_response;
-                    heartbeat_sock.recv(msg_response, zmq::recv_flags::none);
-                    //std::cout << "Heartbeat Response: " << std::endl;
-                } else {
-                    std::cout << "Bella Server is unavailable" << std::endl;
-                    break;
-                }
-            }
-
-            if (items[1].revents & ZMQ_POLLIN) {
-                // Gather input from console
-                std::string input;
-                std::getline(std::cin, input);
-                // Parse the line
-
-                zmq::message_t msg_command (input);
-                command_sock.send(msg_command, zmq::send_flags::none);
-                std::cout << "Sent: " << input.data() << std::endl;
-
-                // Wait for response (poll for ZMQ_POLLIN)
-                zmq::pollitem_t response_item = { command_sock, 0, ZMQ_POLLIN, 0 };
-                zmq::poll(&response_item, 1, 100); // Wait for response with timeout
-
-                /*if (response_item.revents & ZMQ_POLLIN) {
-                    zmq::message_t zmq_response;
-                    command_sock.recv(zmq_response, zmq::recv_flags::none);
-                    std::string response(static_cast<char*>(zmq_response.data()), zmq_response.size());
-                    std::cout << "Server Response: " << response << std::endl;
-                } else {
-                    std::cout << "Server Timeout" << std::endl;
-                    break;
     }*/
-                zmq::message_t zmq_response;
-                command_sock.recv(zmq_response, zmq::recv_flags::none);
-                std::string response(static_cast<char*>(zmq_response.data()), zmq_response.size());
-                std::cout << "Server Response: " << response << std::endl;
 
-                if(input == "exit") {
+    std::string client_pkey_str(client_pkey);
-                    break;
+    std::string client_skey_str(client_skey);
-                } else if(input == "send") {
+
-                    std::string read_file = "./orange-juice.bsz";
+    // Multithreaded
-                    std::cout << "sending\n";
+    std::thread command_t(command_thread, server_pkey, client_pkey_str, client_skey_str);
-                    std::ifstream binaryInputFile;
+    std::thread heartbeat_t(heartbeat_thread, server_pkey, client_pkey_str, client_skey_str);
-                    binaryInputFile.open(read_file, std::ios::binary);// for reading
+
-                    //std::ifstream binaryInputFile(read_file, std::ios::binary);
-                    std::vector<char> send_buffer(chunk_size);
-                    std::streamsize bytes_read_in_chunk;
     while (true) {
-                        binaryInputFile.read(send_buffer.data(), chunk_size); // read the file into the buffer
+        if (!heartbeat_state.load()) {
-                        bytes_read_in_chunk = binaryInputFile.gcount(); // Actual bytes read
+            std::cout << "Dead" << std::endl;
-                        if(bytes_read_in_chunk > 0){
-                            //std::cout << bytes_read_in_chunk << std::endl;
-                            zmq::message_t message(send_buffer.data(), bytes_read_in_chunk);
-                            zmq::message_t z_in;
-                            command_sock.send(message, zmq::send_flags::none);
-                            command_sock.recv(z_in); // Wait for acknowledgment from server
-                        } else {
-                            //zmq::message_t message("");
-                            //zmq::message_t z_in;
-                            //command_sock.send(message, zmq::send_flags::none);
-                            //command_sock.recv(z_in); // Wait for acknowledgment from server
             break;
         }
-                    }
-                    // Send an empty message to signal end of file
-                    command_sock.send(zmq::message_t(), zmq::send_flags::none);
-                    zmq::message_t z_in;
-                    command_sock.recv(z_in); // Wait for acknowledgment from server
-                }
-            }
         std::this_thread::sleep_for(std::chrono::milliseconds(500));
     }
-        heartbeat_sock.close();
+    command_t.join();
-        command_sock.close();
+    heartbeat_t.join();
-        ctx.close();
     return 0;
-    } catch (const zmq::error_t& e) {
-        std::cerr << "ZeroMQ error: " << e.what() << std::endl;
-        return 1;
-    }
 }
 

server.cpp

@@ -2,10 +2,127 @@
 #include <fstream>
 #include <thread>
 #include <zmq.hpp>
-#include <unistd.h>
 #include <vector>
 #include <chrono>
 
+#include <atomic>
+#include <condition_variable>
+#include <mutex>
+
+
+// Atomic variable to store the counter value
+//std::atomic<int> counter(0);
+std::atomic<bool> heartbeat_state (true);
+// Condition variable to signal the counter thread
+//std::condition_variable cv;
+// Mutex to protect shared data
+//std::mutex mtx;
+// Flag to indicate if the counter should reset
+std::atomic<bool> shouldReset(false);
+
+
+void command_thread(std::string server_skey) {
+    zmq::context_t ctx;
+
+    // Create zmq rep sockets
+    //zmq::socket_t heartbeat_sock(ctx, zmq::socket_type::rep);
+    zmq::socket_t command_sock(ctx, zmq::socket_type::rep);  
+    command_sock.set(zmq::sockopt::curve_server, true);
+    command_sock.set(zmq::sockopt::curve_secretkey, server_skey);
+    command_sock.set(zmq::sockopt::linger, 1); // Close immediately on disconnect
+    command_sock.bind("tcp://*:5556");
+    while (true) {
+        zmq::message_t msg_command;
+        command_sock.recv(msg_command, zmq::recv_flags::none);
+        std::string client_command = msg_command.to_string();
+        std::cout << "Command: " << client_command << std::endl;
+
+        if(client_command == "hello"){
+            std::cout << "bye" << std::endl;
+            zmq::message_t zmsg1("bye");
+            command_sock.send(zmsg1, zmq::send_flags::none); 
+        } else if (client_command == "exit") {
+            std::cout << "ACK" << std::endl;
+            zmq::message_t zmsg1("ACK");
+            command_sock.send(zmsg1, zmq::send_flags::none); 
+            //heartbeat_state = false;
+        } else if (client_command == "send") {
+            std::ofstream output_file("received_file.bsz", std::ios::binary); // Open file in binary mode
+            if (!output_file.is_open()) {
+                std::cerr << "Error opening file for writing" << std::endl;
+                std::cout << "ERR" << std::endl;
+                zmq::message_t zmsg1("ERR");
+                command_sock.send(zmsg1, zmq::send_flags::none); 
+            } else {
+                std::cout << "file good ACK" << std::endl;
+                zmq::message_t zmsg1("ACK");
+                command_sock.send(zmsg1, zmq::send_flags::none); 
+                while (true) {
+                    zmq::message_t recv_data;
+                    command_sock.recv(recv_data, zmq::recv_flags::none);
+                    if (recv_data.size() == 0) {
+                        //std::cout << "chunk ACK" << std::endl;
+                        zmq::message_t reply("ACK");
+                        command_sock.send(reply, zmq::send_flags::none);
+                        break; // End of file
+                    } else if(recv_data.size() == 4)  { //LIKELY ERR\0 from client, can't find file
+                        // [TODO] , parse lines only send valid commands
+                        // Right now I allow any text to get through
+
+                        std::cout << "ERR client read ACK" << std::endl;
+                        zmq::message_t reply("ACK");
+                        command_sock.send(reply, zmq::send_flags::none);
+                        break; // End of file
+                    }
+                    //std::cout << recv_data.size() << std::endl;
+                    output_file.write(static_cast<char*>(recv_data.data()), recv_data.size());
+                    zmq::message_t reply("ACK");
+                    command_sock.send(reply, zmq::send_flags::none);
+                }
+                output_file.close();
+            }
+        } else {
+            zmq::message_t zmsg1("foo");
+            command_sock.send(zmsg1, zmq::send_flags::none); 
+        }
+        std::this_thread::sleep_for(std::chrono::milliseconds(10));
+    }
+    command_sock.close();
+    ctx.close();
+}
+
+void heartbeat_thread(std::string server_skey) {
+    heartbeat_state = true;
+    std::cout << "new heartbeat_thread" << std::endl;
+    zmq::context_t ctx;
+    zmq::socket_t heartbeat_sock (ctx, zmq::socket_type::rep);
+    heartbeat_sock.set(zmq::sockopt::curve_server, true);
+    heartbeat_sock.set(zmq::sockopt::curve_secretkey, server_skey);
+    heartbeat_sock.bind("tcp://*:5555");
+    while(true) {
+        zmq::pollitem_t response_item = { heartbeat_sock, 0, ZMQ_POLLIN, 0 };
+        zmq::poll(&response_item, 1, 10000); // Wait for response with timeout
+
+        if (response_item.revents & ZMQ_POLLIN) {
+            zmq::message_t message;
+            heartbeat_sock.recv(message, zmq::recv_flags::none);
+            //std::cout << "heart:" << heartbeat_state.load() << std::endl;
+        
+            std::string response = "Heartbeat OK";
+            zmq::message_t zmq_response (response);
+            heartbeat_sock.send(zmq_response, zmq::send_flags::dontwait); // No block
+        
+        } else {
+            std::cout << "Bella Client Lost" << std::endl;
+            heartbeat_state = false;
+        }
+
+        std::this_thread::sleep_for(std::chrono::milliseconds(100));
+    }
+    heartbeat_sock.close();
+    ctx.close();
+}
+
 // Blocking zmq rep socket to pass server_public_key
 void pkey_server(const std::string& pub_key) {
     zmq::context_t ctx;
@@ -25,12 +142,6 @@ void pkey_server(const std::string& pub_key) {
 
 int main()
 {
-    zmq::context_t ctx(1);
-
-    // Create zmq rep sockets
-    zmq::socket_t heartbeat_sock(ctx, zmq::socket_type::rep);
-    zmq::socket_t command_sock(ctx, zmq::socket_type::rep);  
-
     // Generate brand new keypair on launch
     // [TODO] Add client side public key fingerprinting for added security
     char skey[128] = { 0 };
@@ -41,106 +152,27 @@ int main()
         exit(EXIT_FAILURE);
     }
 
-    heartbeat_sock.set(zmq::sockopt::curve_server, true);
+    // Multi threading
-    heartbeat_sock.set(zmq::sockopt::curve_secretkey, skey);
+    //std::thread command_t(command_thread, skey);
-
+    //std::thread heartbeat_t(heartbeat_thread, skey);
-    command_sock.set(zmq::sockopt::curve_server, true);
+    //std::thread command_t(command_thread, skey);
-    command_sock.set(zmq::sockopt::curve_secretkey, skey);
+    //std::thread heartbeat_t(heartbeat_thread, skey);
-
+    std::thread command_t(command_thread, skey);
-    //heartbeat_sock.set(zmq::sockopt::rcvtimeo, 10000);
+    std::thread heartbeat_t(heartbeat_thread, skey);
-    //heartbeat_sock.set(zmq::sockopt::sndtimeo, 10000);
-    command_sock.set(zmq::sockopt::linger, 1); // Close immediately on disconnect
-
-    // Binding to transport
-    heartbeat_sock.bind("tcp://*:5555");
-    command_sock.bind("tcp://*:5556");
-
-    // Create poll items
-    std::vector<zmq::pollitem_t> items = {
-        { heartbeat_sock, 0, ZMQ_POLLIN, 0 },
-        { command_sock, 0, ZMQ_POLLIN, 0 }
-    };
 
                                        //
-    while(true) { // awaiting client loop
+    while(true) { // awaiting new client loop
+        heartbeat_state = true;
         pkey_server(pkey); // blocking wait client to get public key on port 5555
+        heartbeat_state = true;
         std::cout << "Client connected" << std::endl; 
-        int heartbeat_miss = 0;
-        while (true) { //loop forever accepting encrypted messages, limit to one client
-            zmq::poll(items, 100);    
-            //std::cout << "heart:" << heartbeat_miss << std::endl;
 
-             // Check if heartbeat_socket has data
+        while(true) { // inner loop
-            if (items[0].revents & ZMQ_POLLIN) {
+            //std::cout << "inner loop" << std::endl; 
-                zmq::message_t message;
+            if (heartbeat_state.load()==false) {
-                heartbeat_sock.recv(message, zmq::recv_flags::none);
+                std::cout << "client dead" << std::endl;
-                //std::cout << "heart:" << heartbeat_miss << std::endl;
-
-                std::string response = "Heartbeat OK";
-                zmq::message_t zmq_response (response);
-                heartbeat_sock.send(zmq_response, zmq::send_flags::dontwait); // No block
-                heartbeat_miss = 0; // Reset heartbeat misses
-            } else { //No heartbeat detected during poll
-                heartbeat_miss++;
-                if (heartbeat_miss>25) { //This many misses means client is AWOL
-                    break; //Exit inner loop to outer loop handling pubkey serving
-                }
-            }    
-            // Check if command_socket has data
-            if (items[1].revents & ZMQ_POLLIN) {
-                zmq::message_t msg_command;
-                command_sock.recv(msg_command, zmq::recv_flags::none);
-                std::string client_command = msg_command.to_string();
-                //std::string received_message (static_cast<char*>(msg_command.data()), msg_command.size());
-                std::cout << "Command: " << client_command << std::endl;
-
-                // Send a response
-                //zmq::message_t zmq_response("ACK");
-                //command_sock.send(zmq_response, zmq::send_flags::none);
-                
-                //std::string client_command = msg_command.to_string();
-
-                // 2. Check if the string is empty
-                //if (client_command.empty()) {
-                //    std::cerr << "Invalid message received: "  << std::endl;
-                //    break; // exit loop to await new client
-                //}
-                
-                if(client_command == "hello"){
-                    zmq::message_t zmsg1("bye");
-                    command_sock.send(zmsg1, zmq::send_flags::none); 
-                } else if (client_command == "exit") {
-                    zmq::message_t zmsg1("exit");
-                    command_sock.send(zmsg1, zmq::send_flags::none); 
                 break;
-                } else if (client_command == "send") {
-                    std::ofstream output_file("received_file.bsz", std::ios::binary); // Open file in binary mode
-                    if (!output_file.is_open()) {
-                        std::cerr << "Error opening file for writing" << std::endl;
-                        return 1;
             }
-                    zmq::message_t zmsg1("ACK1");
-                    command_sock.send(zmsg1, zmq::send_flags::none); 
-                    while (true) {
-                        zmq::message_t recv_data;
-                        command_sock.recv(recv_data, zmq::recv_flags::none);
-                        if (recv_data.size() == 0) {
-                            zmq::message_t reply("ACK2");
-                            command_sock.send(reply, zmq::send_flags::none);
-                            break; // End of file
-                        }
-                        //std::cout << recv_data.size() << std::endl;
-                        output_file.write(static_cast<char*>(recv_data.data()), recv_data.size());
-                        zmq::message_t reply("ACK2");
-                        command_sock.send(reply, zmq::send_flags::none);
-                    }
-                    output_file.close();
-                } else {
-                    zmq::message_t zmsg1("ACK");
-                    command_sock.send(zmsg1, zmq::send_flags::none); 
-                }
-            }
-            // Simulate doing other work (optional)
             std::this_thread::sleep_for(std::chrono::milliseconds(10));
         }
     }